鄂西山地的酸性棕壤和灰棕壤形成条件及理化性质

根据鄂西山地的自然成土条件，分析了酸性棕壤、灰棕壤诊断层和诊断特性，主要理化性质和粘土矿物组成，结果表明：酸性棕壤和灰棕壤同属于亚热带中山上部或亚高山中上部冷湿条件下形成的森林土壤。其理化性质与我国北方同类土壤又有较大差别。

FORMATION CONDITIONS AND PHYSICO-CHEMICAL PROPERTIES OF ACID BROWN SOILS AND GREY BROWN SOILS IN THE MOUNTAINOUS AREAS OF WEST HUBEI

The profile morphology,main physico-chemical properties and clay mineral composition of acid brown soil,grey brown soil are disscussed according to the natural conditions of the mountain soil formation in the west Hubei.The results show that both of the acid brown soil and grey brown soil belong to the forest soils formed in the middle and upper parts of subalpine and medium mountain areas in the subtropic climatic zone under cold and humid conditions.But their physico-chemical properties differed obviously with the same soil types in the northern China.The acid brown soils are distributed in the middle and upper parts of the medium altitude mountains,with an altitude higher than the dark yellow-brown soils,being the forest soils with the vegetations of bright conifer and broadleaf deciuous scrubs.Their distribution altitude is higher in the southwest Hubei than in the Northwest Hubei.Grey brown soil is the forest soil formed under colder and more humid conditions than the acid brown soil and located at a higher altitute than the acid brown soil about 2500m above the sea level in Shen nongjia region,and its vegetations are dark conifer forests.